Autor: |
Otsuka J; Laboratory for Exercise and Environment Physiology, Faculty of Education, Niigata University, Niigata, Japan., Okamoto Y; Laboratory for Exercise and Environment Physiology, Faculty of Education, Niigata University, Niigata, Japan., Enoki Y; Advanced Research Institutes, Bourbon Corporation, Niigata, Japan., Maejima D; Advanced Research Institutes, Bourbon Corporation, Niigata, Japan., Fujii N; Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan., Kenny GP; Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, Canada., Mündel T; Department of Kinesiology, Brock University, St. Catharines, ON, Canada., Cotter JD; School of Physical Education, Sport and Exercise Sciences, Division of Sciences, University of Otago, Dunedin, New Zealand., Amano T; Laboratory for Exercise and Environment Physiology, Faculty of Education, Niigata University, Niigata, Japan. |
Abstrakt: |
We evaluated changes in hyperhydration and beverage hydration index (BHI, a composite measure of fluid balance after consuming a test beverage relative to water) during resting, induced by the consumption of beverages containing glycerol and sodium supplemented with fast-absorbing sucrose or slow-absorbing isomaltulose. In a randomized crossover, single-blinded protocol (clinical trials registry: UMIN000042644), 14 young physically active adults (three women) consumed 1 L of beverage containing either 7% glycerol + 0.5% sodium (Gly + Na), Gly + Na plus 7% sucrose (Gly + Na + Suc), Gly + Na plus 7% isomaltulose (Gly + Na + Iso), or water (CON) over a 40 min period. We assessed the change in plasma volume (ΔPV), BHI (calculated from cumulative urine output following consumption of water relative to that of the beverage), and blood glucose and sodium for 180 min after initiating ingestion. Total urine volume was reduced in all beverages containing glycerol and sodium compared to CON (all P ≤ 0.002). The addition of isomaltulose increased BHI by ∼45% (3.43 ± 1.0 vs. 2.50 ± 0.7 for Gly + Na, P = 0.011) whereas sucrose did not (2.6 ± 0.6, P = 0.826). The PV expansion was earliest for Gly + Na (30 min), slower for Gly + Na + Suc (90 min), and slowest for Gly + Na + Iso (120 min) with a concomitant lag in the increase of blood glucose and sodium concentrations. Supplementation of beverages containing glycerol and sodium with isomaltulose but not sucrose enhances BHI from those of glycerol and sodium only under a resting state, likely due to the slow absorption of isomaltulose-derived monosaccharides (i.e., glucose and fructose). |